Remote frequency indicator



[W NDOWS] MIG! CVCtFs R. A. EG BERT REMOTE FREQUENCY INDICATOR FiledFeb. 2, 1960 May 15, 1962 ,Q/cbam .4. Egbert %412? nited States PatentOffice 3,035,256 Patented May 15, 1962 3,035,256 REMOTE FREQUENCYINDICATOR Richard A. Egbert, Chesterland, Ohio, assignor to ThompsonRamo Wooldridge Inc., Cleveland, Ohio, a corporation of Ohio Filed Feb.2, 1960, Ser. No. 6,266 9 Claims. (Cl. 340-315) This invention relatesto an indicator, for use at a master or control station, to visuallyshow the exact numerical frequency of a remote, connected tuner receiveror the like. More particularly this invention relates to such a remotefrequency indicator of the type having a selsyn electric motorcontrolled, and moving in accordance with, a transmitter correspondingto the frequency of a remote tuner or the like, said selsyn beingoperatively connected to drive a counter which always supplies avisible, numerical indicia of the frequency of the corresponding andconnected remote tuner, and said indicator including manually operablyreset means to synchronize the counter indicator with the frequency ofthe remote tuner when necessary.

The general objects of this invention reside in the provision of animproved remote and manually resettable frequency indicator, of thistype which is small and light to be suitable for airborne use and yet isreliable, stable, trouble free and convenient in its normal and in itsreset operation or use.

A further object of this invention is the provision of such anindicator, including as an operative part thereof, an improved andmanually adjustable reset means to permit periodic synchronization ofthe counter with the frequency of the remote tuner without in any waydisturbing or moving the selsyn repeater motor during such manualadjustment.

Another and more detailed object of this invention is the provision ofsuch an indicator including a drive permitting a slip clutch actuationof the counter to synchronize it with the frequency of the remote tuneronly when necessary by a special and foolproof manual motion of therotary reset shaft to thereby prevent angular motion of the selsyn motoronly during the actual interval of such manual adjustment.

This invention contemplates other objects, features and advantages whichwill become more fully apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings which illustrate apreferred embodiment, and in which:

FIGURE 1 is a sectional view taken on the line 1-1 of FIGURE 3, withcertain interior parts shown in full;

FIGURE 2 is a reduced scale, rear elevational view of an assembly unitor set of three of the indicators corresponding to this invention;

FIGURE 3 is a front elevational view of the assembly as shown in FIGURE2; and

FIGURE 4 is a scale, sectional view taken on the line IV-IV of FIGURE 3,and with certain interior parts shown in full.

The separate and preferably identical selsyn actuated, frequencyindicating units, each designated as a whole by numeral 1, areparticularly intended to be used in assemblies or sets of a plurality,or up to three, mounted as shown in a single or common case or box,which is designated as a whole by 2. A desired or suitable number ofsuch assemblies or boxes (which may, for example, give a total of nineindicator units) are suitably mounted, as on the front of the countermeasure system console or control panel in an airplane, with each case2, extending across the width of such panel or console.

Such group of sets of units permits visual monitoring or observing ofthe frequency of each of a plurality of remote but suitably connectedstations, or the tuners of remote receivers of a system (such as acounter-measures system) having a plurality of remote and periodicallydifferently tuned, counter-measures receivers. These remote receiversare each to be tuned from the same master station by suitable orconventional but non-illustrated means. Each indicator unit 1 issuitably connected to be energized by, and to respond to, itscorresponding remote selsyn transmitter at the tuner of thecorresponding remote receiver. Such operative connections and suchremote receiver-tuner controls are not further described or illustratedherein since they may be of any suitable or known type and are wellunderstood by those skilled in this art.

Thus, according to the system and the units of the present invention,the system operator can instantly, and without having to reset anycounter as he switches from tuner to tuner, visually observe the currentor existing frequency of each of the plurality of the remote receiversof the system.

It is to be noted that heretofore a single or only one larger andheavier (and less efiicient) remote receiver indicating unit and counterwas employed for all of the plurality of receivers or tuners in thesystem. This required that the operator had to reset this single (largerand heavier) indicator each time he changed the tuning range. This took,relatively, a substantial period of time, as much as two minutes.

In contrast to the foregoing, the present system (by reason of thesmaller and lighter indicator units of which an appreciable number, suchas the above mentioned nine, can be airborne) eliminates this timeconsuming and error producing resetting operation for the reading ofeach station and permits the operator to instantly read the tuning ofany one of the remote stations or receivers. The reset means need onlybe employed when necessary or when a remote receiver is out ofsynchronism with its selsyn connected indicator. Thus, according to thepresent invention, the operator normally has no need to reset anycounter, as he switches from tuner to tuner.

Each indicator, according to this invention, forms a complete andself-contained unit, having its own frame or its own partial casecomprising the top 4, which may, as shown, be formed integrally bybending with the front closure 5 and preferably of thin metal which inthis embodiment, is anodized aluminum. This frame or partial casing alsoincludes the suitably secured and thicker insulating, rear closure 7,and if desired, the suitably secured bottom 6, which is preferably alsoof anodized aluminum. While it is not essential when units 1 are mountedin the assembly boxes 2, yet it will be understood that each unit 1, mayif desired, be completely eucased.

A plurality of such indicator units, preferably up to three as shown,are suitably mounted and secured in a set or assembly, case 2 whichcomprises the front 9, the sides 11 and 12, the back 13, the top 14 andthe bottom 15, all suitably secured together and all preferably ofanodized aluminum.

A suitable, translucent and edge-lit front or display panel 18 issuitably secured to the front closure 9 and carries suitable markingsand the several actuating knobs or controls thereon as shown in FIGURE2. As noted above, a plurality of such three unit wide assemblies 2 maybe mounted one on top of the other for all or part of the height of thesuitable control console.

A selsyn motor 20 is suitably mounted, as by the em bracing strap 21which is in turn suitably secured to the casing top, and if desired, tothe casing bottom 6 as indicated in FIGURE 4. The details or interior ofthe selsyn 20 are not further disclosed or illustrated herein since anyknown or suitable type may be employed, as will be well understood bythose skilled in this art.

This selsyn motor is suitably energized and controlled, as by wires 23extending from the connector plug 25. This plug extends outwardlythrough corresponding holes in the rear walls 7 and 13 and is suitablysecured to wall 7, as by screws27. It will be noted that walls 13 and 7may be secured together as by suitable rivets 29 having inner head means31 compressing springs, such as 30, between them and the wall 7 tothereby provide vibration absorption and to take up all clearance in thesecuring together of several units 1 to common wall 13.

The front end of the selsyn motor 29 is suitably secured to the rear ofthe gear casing which is designated as a whole by 34 and encloses forboth the counter and the gear drive. This securing or mounting may be bymeans of an outwardly extending flange 32 on the front of thecylindrical casing of the selsyn motor 20 connected by screws 33 to therear end portion 43 of the drive and counter casing 34.

This casing 34 comprises the side walls 39 and 40 which may, if desired,be formed integral with the rear wall 43, the front wall 41, the topwall 37, and bottom wall 38, are all suitably connected and of suitablyrigid and light material. The bottom wall 38 has a downwardly extendingleg or extension 38A to engage the bottom wall 6.

The selsyn motor has its rotary shaft projecting from its front andengaged in a corresponding socket, in which it is secured by set screw47, of the sleeve and bevel gear member 46. Gear 46 is always meshedwith bevel gear and sleeve 48, which has a friction drive or slip clutchtype of connection to its drive shaft 54 by means of the frictionproducing, compression spring 49 which engages its end, said springbeing held in place by the locking ring 50. Thus spring 49 also holdsgear 46 in mesh with gear 48 Also mounted on the other end portion ofdrive shaft 54 is the additional bevel gear 51 rigidly connected to spurgear 52 which is, in turn, rigidly mounted on shaft 54 as by the setscrew 53. The bevel gear and sleeve 55 is normally free from, 'or out ofengagement with, gear 51. Gear 55 is suitably and rigidly mounted, as byset screw 55a, on the rotary and axially reciprocable plunger element orshaft 56 which has the actuating knob 57 rigidly mounted on its exposedor outer end.

The shaft and plunger 56 extends through suitable holes in the severalfront walls, including the seal and bearing 60 in wall 18 and the sealand bearing member 59 in wall 41.

This plunger-shaft 56 is held in its outer, or disengaged, position, asshown, by the conical spring 62 which is compressed between front wall41 of the casing 34 and suitable means secured to the plunger shaft 56such as the leaf spring lever 64 which is secured to the shaft to permitthe shaft to extend through, and to rotate in, a hole in this lever.Axial motion of the shaft relative to lever 64 is prevented by theretaining ring 65 fixed on the shaft and engaging lever 64 as shown. Theinner or fixed end of the lever or leaf spring 64 is suitably secured oncasing 34 as by the screw 67 through a hole in the inner end of springlever 64. It will be noted that the spring lever 64 also engages,intermediate its length, a plunger 69 which is reciprocably slidable ina suitable hole through the front wall 41 of the casing 34 so that itsinner end can engage the knurled cylindrical surface of the gear andsleeve member 48 to serve as a brake to hold or lock member 48 againstrotary motion (through its slip clutch connection by 49 to the shaft 54)when the plunger-shaft 5657 is pushed into its operative positionagainst the compression spring 62 and the springiness of 64.

When it does become necessary to reset the angular position of thecounter mechanism is adjusted, relative to motor 2%), by rotation ofgear 51 and connected spur gear 52, which connects to the input or unitend of any suitable or conventional indicating type of counter stack 4mechanism such as the Veeder-Root unit which is Well known to thoseskilled in this art and hence not further illustrated herein.

Thus, during this occasional reset operation, pushing in of plunger androtary shaft 56 simultaneously brakes or locks 48 (and hence the selsynmotor) against any angular motion and simultaneously permits the resetadjustment of the counter by rotation of shaft 56 through the clutchedor meshed in gear 55, which then engages with gear 51.

It may be noted that gears 46, 48, 51 and 55 may be of variousconventional types but are here illustrated as bevel or miter gearshaving angles of 45. It is also to be noted that spring 49 not onlyserves as the friction drive or slip clutch, but it furnishes theresilient bias to maintain gear 48 in meshing and operative engagementwith gear 46. It will also be noted that 57 may be considered as a pushbutton, which when pushed in locks up the selsyn motor 20 and engagesthe counter drive gear unit 51 to rotate the same upon rotation of thebutton or knob 57. If button or knob 57 is rotated without being pushedin, there will be no effect, so that these controls are foolproof inpreventing improper actuation.

The brake plunger 69 is slidably mounted in a suitable hole in the geardrive casing front 41 and has its enlarged head engaging under thespring lever 64. This same head 69A engages, and is outwardly biased bythe compression spring 71, which is seated and retained in a suitablerecess 71A in front 41. It is to be noted that spring 71 normally holdsthe inner or brake end of plunger out of engagement with the knurledperiphery of gear sleeve 48. This spring 71 and spring 62 (and thespringiness of lever 64) cooperate in holding the whole unit in itsoperative position.

The translucent front panel 18 has a counter window or opening throughwhich the indicating numerals on the wheels of the horizontal axiscounter stack are visible. Knob 72 may be used to control the normalpanel lighting and knob 73 to control the edge lighting of 18.

It is to be understood that various modifications or changes may be madewithout departing from the spirit or scope of this invention as definedin the appended claims.

I claim as my invention:

1. A remote receiver frequency indicating unit for a multiple-receiverradio system comprising a selsyn electric motor having means tooperatively connect it to said remote station, a rotary counter tovisually indicate frequency, drive means connected therebe-tweenincluding bevel gears connecting said motor to a transverse drive shaftthrough spring held, friction, slip clutch means, said shaft beingconnected to drive said indicator and having an additional bevel gearthereon, normally inoperative brake means to hold said motor againstrotation, and an axially movable and rotatable, manually operable, resetshaft extending transverseto said connecting shaft and substantiallyparallel to said motor, a spring biased lever urging said shaft axiallytowards its inoperative position and also engaging said brake means toactuate it upon axial motion of said reset shaft into its operativeposition, and a bevel gear upon the inner end of said reset shaft to bemeshed with said additional bevel gear upon said axial motion of saidreset shaft into its operative position to thereby rotate said indicatorin either direction upon rotation of said reset shaft while so engaged.

2. A remote radio receiver frequency indicator unit comprising a unitframe forming at least a partial boxlike casing which is elongated fromfront to back, a selsyn electric motor centrally therein and having ashaft extending axially of the length of said frame, means in the rearof said frame to operatively connect said motor to a remote receiver, atransversely extending and visible counter indicator in the front ofsaid frame and having a connected drive shaft extending transversely tosaid motor, a bevel gear on said motor shaft, a meshing bevel gearhaving connected brake means and being on said transverse drive shaftand connected thereto by a friction slip clutch, an additional bevelgear on said drive shaft, and an axially extending and movable resetshaft having a bevel gear thereon normally held disengaged from saidadditional bevel gear with said additional bevel gear and tosimultaneously engage and actuate said brake means to hold said motoragainst rotation by slippage of said clutch, to thereby permit rotationof said counter in either direction relative to said motor.

3. A retote station frequency indicating unit comprising a case having afront with a Window opening therein, a counter stack indicator in saidcase and having numerals visible through said window opening, a selsynelectric motor in said case and having means to operatively connect itto said remote station, drive means normally interconnecting said motorand said indicator and including clutch and brake means, manuallyoperable means extending into said casing and connected to reset saidindicator by simultaneously holding said motor against rotation by saidbrake means to permit slippage of said clutch means to thus preventmotor rotation by one motion of said manually operable means and meansmanually engaged by said manually operable means while so held toangularly move said indicator in either direction upon another motion ofsaid manually operable means, and resilient means to normally hold saidmanually operable means in its inoperative position and said drive meansin its operative position.

4. A remote receiver frequency indicator unit comprising a case having afront with a window opening therethrough, a rotary counter stackindicator means therein having its frequency indicating numerals visiblethrough said Window, a selsyn electric motor in said case, drive meansconnecting said motor and said counter means and including a normallyengaged slip clutch means, a brake means to hold said motor, andmanually operable reset means to shift the angular relation between saidcounter means and said motor to reset said indicator means to the thenreceiver frequency comprising means including a shaft extendingtransversely through said casing front to engage said brake means tohold said motor and permit slippage of said clutch means upon axialmotion of said reset shaft and to angularly move said counter means ineither direction relative to said motor upon rotation of said resetshaft while it is engaging said brake means.

5. A remote radio receiver frequency indicating unit comprising a casehaving a visible and reversibly rotatable frequency indicator therein, aselsyn electric motor in said case having a shaft and having means tooperatively connect it to said remote station, drive means normallyinterconnecting said motor shaft and said indicator and including adrive shaft extending transversely to, and connected to, said motorshaft, said drive shaft having slip clutch means and brake meansthereon, and reset means including a plunger shaft adjacent to, andsubstantially parallel to, said motor shaft, spring means to hold saidshaft in its outer inoperative position, said shaft being axiallymovable inwardly to engage said brake means and hold said motor topermit slippage of said clutch means, and said shaft including means torotatably actuate said indicator in either direction when said shaft isin its inner operaive position.

6. A remote frequency indicator unit comprising a reversable selsynelectric motor having a shaft, an axially extending drive and indicatorcasing connected to the end of said motor and enclosing its shaft, avisible and reversibly rotatable indicator in said casing, drive meansin said casing normally operatively connecting said motor shaft and saidindicator, said drive means including a drive shaft journaled at eachend in said casing and extending transverse to, and operably connectedto, said motor shaft and having slip clutch means and brake meansthereon, manual reset means including a shaft plunger journaled in saidcasing for axial motion and rotary motion, a compression coil springacting between said casing and said shaft to normally hold it in itsaxially outer and inoperative position, a lever engaged by said springand said shaft plunger to actuate said brake means and permit slippageof said clutch means when said plunger is held manually in its inneroperative position, and gear means engaged when said plunger is in itsinner operative position to angularly adjust said indicator in eitherdirection relative to said motor.

7. A remote radio station frequency indicating unit comprising a selsynelectric motor having means to operatively connect it to said remotestation and having a shaft, a reversibly rotatable frequency indicator,drive means normally interconnecting said motor shaft and saidindicator, a drive and indicator casing extending from, and connectedto, said motor and enclosing its shaft and enclosing said drive meansand said indicator, said drive means including a drive shaft extendingtransverse to, and operatively connected to, said motor shaft and havingslip clutch means and a brake means thereon, manual reset meansincluding an axially reciprocable brake plunger slidably mounted in saidcasing and having spring means to hold it in its inoperative position,said brake plunger being positioned to operatively engage said brakemeans, and reset means including a shaft plunger journaled in saidcasing for axial and for rotary motion and having a compression springacting between said casing and said shaft to normally hold it in itsinoperative outer position, a lever pivotally mounted on the outside ofsaid casing, engaging said brake plunger and engaging, and actuated by,said shaft plunger whereby said shaft, when held in its inner operativeposition, actuates said brake to permit slippage of said clutch uponrotation of said indicator relative to said motor, and means engagedupon axial motion of said plunger shaft to its inner position toangularly adjust said indicator.

8. An indicator unit to visually show the frequency of a remote radioreceiver comprising a selsyn motor having means to operatively connectit to said remote receiver and a shaft, a drive and indicator casingconnected to the end of said motor and enclosing said motor shaft, avisible and rotary frequency indicator in said casing, drive means insaid casing normally operatively connecting said motor shaft and saidindicator, said drive means including a transverse drive shaft and apair of bevel gears interconnecting said motor shaft and said driveshaft, spring means providing a slip clutch and also holding one of saidbevel gears in meshing engagement with the other of said bevel gears,one of said bevel gears having means providing a brake to hold saidmotor, and manually operable, reset means to actuate said brake meansand permit slippage of said clutch means, said manually reset meansincluding means to rotate said indicator in either direction relative tosaid motor.

9. A remote receiver frequency indicator unit comprising a rotaryfrequency indicator, a selsyn electric motor, drive means between saidindicator and said motor including a normally engaged slip clutch means,a brake means to hold said motor, and a unitary manually operable resetmeans movable in one direction to actuate said brake means to permitslippage of said clutch means and simultaneously movable in anotherdirection for actuating said rotary indicator independently of saidmotor by said slippage of said clutch means.

References Cited in the file of this patent UNITED STATES PATENTS1,375,437 Akemann Apr. 19, 1921 2,750,585 Anderson et al June 12, 1956FOREIGN PATENTS 793,869 France Feb. 3, 1956

